package demo1;
import java.util.ArrayList;
import java.util.Collection;
public class Test01 {
    public static void main(String[] args) {
        Collection c = new ArrayList();
        c.add(123);
        c.add("sss");
        System.out.println(c.size());
        System.out.println(c.contains(123));
        c.clear();
        System.out.println(c.size());
        System.out.println(c.isEmpty());
    }
}
